Lucy is a dress maker. She sews 4/7 of a dress in 3/4 hour. At this rate, how many dresses does Lucy sew in one hour?

1 Answer
Dec 30, 2016

Answer:

#16/21 " dresses"#

Explanation:

The ratio of time required to dresses made is
#color(white)("XXX")3/4* k " hours" : 4/7 * k " dresses"# for any constant #k#

Specifically, if we want #1 " hour"# then #k# will need to be #color(green)(4/3)#.

So #(color(red)(cancel(color(black)3)))/(color(blue)(cancel(color(black)4)))xx(color(blue)(cancel(color(green)4)))/(color(red)(cancel(color(green)3))) " hours" : 4/7 xx color(green)(4/3) " dresses"#

#rArr 1 " hour" : 16/21 "dresses"#